Bulldozers and other material moving work machines are frequently used at work sites to move material around the work site and alter the terrain of the work site. Traditionally, bulldozers were commandeered by an operator controlling the movement, blade position, and other aspects of the bulldozer from an operator area, such as a cabin, of the bulldozer. The operator uses their knowledge of the bulldozer, current worksite terrain, and desired terrain to control the actions of the bulldozer and create the desired terrain in the work site.
As more functions and controls have been introduced to material moving work machines, it has become more difficult for operators to effectively keep track of and control all operating parameters of work machines. Further, operators may not be able to adequately control the work machine to deal with issues that develop as the work machine moves terrains, such as the work machine slipping due to unpredictable material movement as the work machine moves material. Operators also typically control the work machines based on their “feel” for the machine and its operation, which leaves room for significant inefficiencies.
To address some of the issues associated with operators manually controlling material moving work machines, autonomous work machines have been developed which provide varying degrees of autonomy to the operation of the work vehicle through a controller system. One example of such a system is described in U.S. Pat. No. 7,865,285 to Price et al., which incorporates a machine mounted stereo imaging apparatus to assist in autonomously controlling the movement of the work machine based on a desired terrain map of the work site compared to a current map of the work site which is generated from one or more images of the work site. One particular problem with the system described by Price et al. is that relying on visual images of the work site to generate the current map of the work site does not take into account how the material may shift while being moved by the work machine. If material shifts in such a way that obstructs the visualizing element(s) of the work vehicle, the current map of the work site will be inaccurate without an additional image from another vantage point, which complicates the system and increases the cost. Further, such a system cannot adequately predict and compensate for material shift that naturally occurs as the work machine moves material across the worksite.
What is needed in the art is a work machine which can address some of the previously described issues which are known in the prior art.